git installation fails in home directory on ubuntu 12.04

So I did
git fetch
git rebase
git describe
v1.7.12-503-g5976753

./configure --prefix=/home/sb
make
make install

    GEN perl/PM.stamp
    SUBDIR gitweb
    SUBDIR ../
    SUBDIR perl

make[1]: `perl.mak' is up to date.
make[2]: `GIT-VERSION-FILE' is up to date.
GEN git-instaweb
SUBDIR git-gui
SUBDIR gitk-git
make[1]: Nothing to be done for `all'.
SUBDIR perl
SUBDIR git_remote_helpers
SUBDIR templates
install -d -m 755 '/home/sb/bin'
install -d -m 755 '/home/sb/libexec/git-core'
install git-credential-store git-daemon git-fast-import
git-http-backend git-imap-send git-sh-i18n--envsubst git-shell git-show-index git-upload-pack git-http-fetch git-http-push git-credential-cache git-credential-cache--daemon git-remote-http git-remote-https git-remote-ftp git-remote-ftps git-am git-bisect git-difftool--helper git-filter-branch git-lost-found git-merge-octopus git-merge-one-file git-merge-resolve git-mergetool git-pull git-quiltimport git-rebase git-repack git-request-pull git-stash git-submodule git-web--browse git-add--interactive git-difftool git-archimport git-cvsexportcommit git-cvsimport git-cvsserver git-relink git-send-email git-svn git-remote-testgit git-p4 git-instaweb '/home/sb/libexec/git-core'
install -m 644 git-mergetool--lib git-parse-remote git-rebase--am git-rebase--interactive git-rebase--merge git-sh-setup git-sh-i18n '/home/sb/libexec/git-core'
install git git-upload-pack git-receive-pack git-upload-archive git-shell git-cvsserver '/home/sb/bin'
make -C templates DESTDIR='' install
make[1]: Entering directory `/home/sb/OSS/git/templates' install -d -m 755 '/home/sb/share/git-core/templates'

(cd blt && tar cf - .) | \
	(cd '/home/sb/share/git-core/templates' && umask 022 && tar xof -)

make[1]: Leaving directory `/home/sb/OSS/git/templates' install -d -m 755 '/home/sb/libexec/git-core/mergetools' install -m 644 mergetools/* '/home/sb/libexec/git-core/mergetools' install -d -m 755 '/home/sb/share/locale'

(cd po/build/locale && tar cf - .) | \
	(cd '/home/sb/share/locale' && umask 022 && tar xof -)

make -C perl prefix='/home/sb' DESTDIR='' install
make[1]: Entering directory `/home/sb/OSS/git/perl'
make[2]: Entering directory `/home/sb/OSS/git/perl' Appending installation info to /usr/local/lib/perl/5.14.2/perllocal.pod mkdir /usr/local/lib/perl: Permission denied at /usr/share/perl/5.14/ExtUtils/Command.pm line 288
make[2]: [doc_site_install] Error 13 (ignored)
/bin/sh: 1: cannot create /usr/local/lib/perl/5.14.2/perllocal.pod:
Directory nonexistent
make[2]: [doc_site_install] Error 2 (ignored) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
ERROR: Can't create '/usr/local/share/man/man3'
mkdir /usr/local/share/man/man3: Permission denied at /usr/share/perl/5.14/ExtUtils/Install.pm line 494

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
at -e line 1
make[2]: *** [pure_site_install] Error 13
make[2]: Target install' not remade because of errors. make[2]: Leaving directory /home/sb/OSS/git/perl'
make[1]: *** [install] Error 2
make[1]: Leaving directory `/home/sb/OSS/git/perl'
make: *** [install] Error 2

I often do an equivalent of

make prefix=/home/gitster
make prefix=/home/gitster install

and never saw this. I do not use ./configure, and am not actively involved in maintaining that part of the system.

Among the people who touched configure.ac and aclocal.m4 in the past 18 months, Stefano seems to be the most clueful with that part of the system, and among those who touched perl/Makefile.PL during the same period, I suspect Jonathan may know a thing or two about MakeMaker, so let's see if we can get help from these directions...